Friction transmission for motor vehicles



Oct. 13, 1936. J. EHRLICH FRICTION. TRANSMISSION FOR MOTOR VEHICLES Filed May 7, 1954 2 Sheeis-Shet 1 Oct. 13, 1936. J, ucH 2,057,140

FRICTION TRANSMISSION FOR MOTOR VEHICLES Filed May 7, 1934 2 Sheets-Sheet 2 2w 6 3mm X a v 5. m 4 ymmwm Patented Oct. 13, 1936 FRICTION TRANSMISSION ron.

moron. vnmcms Jacob Ehrlich, Detroit, Mich assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application May 7, 1934, Serial No. 724,243 iclalms. (Cl: 74-200) This invention relates to motor-vehicle transmission mechanism utilizing a combination of race-and-friction-roller' elements susceptible of adjustment for infinitely varying the ratio of output to input speed within a limited range.

Among objects of the invention are,-to drive a motor vehicle forward by transmitting the power of the engine to the driving wheels through frictional transmission elements, but to bypass the frictional transmission elements in reverse driving so that no torque is then transmitted through them; to enable the size and weight of the transmission mechanism to be reduced for a given power output; to simplify the problem of securing the roller supporting means to the casing; to afford ready access to the internal mechanism; to reduce losses due to churning of oil in the transmission case; and to facilitate mounting the transmission mechanism rearward of the rear axle in so order to obtain superior weight distribution.

- These and other useful objectives are achieved by the out-of-line arrangement of inputand'output shafts illustrated, which makes possible a;

simplified reverse mechanism disposed between engine and frictional power transmitting elements, thus shunting out .the frictional elements when driving in reverse; the use of any suitable gear ratio between input and output shafts; omission of acoupling drum from input shaft or output shaft to the central race as when driving and driven shafts are alined; extending the input shaft above or below past the rear axle and gearing it back of said axle to the output shaft, the

. axis of which may intersect, if desired, the axis a 'of the rear axle differential to which the output shaft is geared.

In the accompanying drawings, in which like reference characters indicate like parts through- I out the several views:

Fig. 1 is a plan view of a vehicle frame and power plant showing the relative positions of engine and transmission with respect to the frameand driving wheels as contemplated in this 'invention;

Fig. 1a is a cross section showing a mounting for the front end of the differential casing;

Fig. 2 is a side elevation of the differential and variable speed transmission mechanisms partly inclosed by their casings;

Fig. 3 is a fragmentary plan view of the main powerinput shaft and of elements driven thereby;

Fig.3 is transverse section'online 4-4 of Fig. 2;

Figs. 5 and 6 are details of devicesfor manually 5 connecting the engineto the vehicle wheels in forward or reverse gear or for disconnecting both forward and reverse. 7

' Referring to Fig. 1',numeral I I indicates the longitudinal sills of'a motor vehicle frame; I! a cross bar bridging the sills III at their rear ends, 5 and Il a cross bar bridging the sills l0 somewhat forward of the rear driving axles shown at It. The rear portion of the frame is shown as supported on traction wheels ill by springs 20 one end of each of which is connected as by a shackle 10 to a sill It at 22, while the otherend of each is bolted or otherwise rigidly connected to an arm 24 adjacent the end 26, which is pivoted to a sill ID. The free ends of arms 2 support the bearings of the outer ends of the driving axles and 15 the traction wheels. Driving axles it are connected by universal joints 28 to differential mechanism within casing 30. Differential casing 30 is rigidly joined to transmission casing 32. The rear end of casing 32 has a supporting bracket 30 34 which rests on a rubber pad (not'shown) mounted on cross member l2, while the front end of casing 30 is bolted to bracket 36 that rests upon rubber pads 38 on cross bar It. The pad between supporting bracket 34 and cross member I2 is'like pads '38. The casing structure 30, 32, therefore, has a three point cushioned support on the vehicle frame. The traction wheels are independently sprung, and are driven by floating driving axles it from the differential mounted on so the frame as described and illustrated. Referring further to Fig 1, a prime mover such as an engine ll is mounted onthe frame forward of the rear traction wheels. Theengine shaft is. connected to a transmission input shaft 85 42 by a suitable main friction clutch (not shown) within the clutch housing 44. Shaft 42 extends rearward through a bearing in the differential housing 3., above the axis of the differential gearing (as shown in Fig. 2), into the transmission do housing 32.

Input shaft 42 is divided within housing 32 at 46 (Fig. 3) and continues rearward as alined shaft 420. As shown, shaft 42a has a pilot bore in which the rear reduced end of;sliaft 42 is rotatably supported. and said shaft. and alined shaft 42a may be coupled or ,uncoupled at the will of the operator in order to connect or disconnect forward drive. A forward driving gear 18' is secured to shaft 424, and a reverse driving 60 gear 50 is splined to shaft 4!. Rigid with reverse driving gear 50 is a hub 52 having a gear-like clutch member 54 on its rearward end slidable within a cylindrical coupling member 56 fixed to shaft 421:. Said coupling member. extends ll forward concentric with shaft 42, and is equipped with an internal gear-like clutch member 58 adapted to interlock with the external clutch teeth of member 54. Shafts 42 and 42a, when 5 coupled act as one shaft for forward driving.

Output shaft 60, within casing 32, has driving connection with at least one coaxial race 62 (and preferably two), with a reverse gear 68 and a bevel pinion 64 at its front end meshing with 1 the ring gear 66 of a differential set of suitable construction within housing 30.

The output shaft 60, as will be perceived by inspection of the drawings, is at one side (the left as shown) of the longitudinal center line of the frame, while the axis of input shaft 42, 42a is substantially in a vertical, longitudinal, central plane. Ring gear 66 of the differential is reversed from its usual position, facing away from the longitudinal center" instead of toward said center. This construction allows the driving axles to be of equal length, permits the input shaft to pass above (as shown) the differential pinion cage or carrier, and the driving pinion 64 to be disposed well to one side of the center line of the frame.

Coaxial with shaft 60 and rotatable relatively to it is at least one race I0 (preferably two) coupled to a gear 12 to rotate with it, said gear 12 being constantly in mesh with driving gear 48 on input shaft continuation 42a. Between races I0 and 62 power transmitting rollers are disposed in such relation as to transmit rotary movement from race ill to race 62. One of these power transmitting rollers is indicated by reference numeral 14 in Figs. 2 and 3. The transmission designed to be utilized is a friction transmission of the general type disclosed in patent to Hoffman #744,550 or Spencer #751,958, for examples. Any suitable controlling means for changing transmitting ratio may be utilized. As the particular friction transmission structure utilized and the controls therefor form'no part of this invention they are not illustrated.

Although gears 48 and 12 are shown in Fig. 4

as provided with the same number of teeth, the parallel arrangement of input and output shafts illustrated permits of easily providing an fover-' drive, by making gear 48 with a largernumber of teeth than gea'r'12.

5o 5054.is in the position shown in Figs. 2 and 3,

the transmission is in neutral. It is then disconnected functionally both from the engine and the vehicle driving wheels." If this composite element 50-414 be moved one step forward (to the left as shown in Figs. 2 and 3) so as to intermesh clutch elements 54 and 58 the transmission will then be coupled both to the engine and vshicle wheels for forward driving. If from neu- 60 tral position the composite element be moved one step rearward (to the'right as shown in Figs. 2 and 3) then gear 50 will mesh with gear 68 on shaft 60, and engine and vehicle will be coupled in reverse, or for rearward driving. The power 5 then flows through shaft 42, gear 50, gear 68, shaft 60, pinion 64 and: differential gearing to the vehicle dllViIiKgWhEBlS. The friction trans. mission within casing 32 then turns in reverse without transmitting torque.

In order to enable the operator to shift from vided a shifter fork (Figs. 2, 5,- and 6) engagin composite pinion and clutch element 5054 and operator controlled means for moving the shifter 5 fork forward and rearward. This operator coa-' When composite gear and jaw clutch element neutral to forward drive or reverse there is pro-.

trolled means comprises a lever 82 (Figs. 1, 2, 5; and 6) moved by any suitable control device (not shown) disposed within reach of the operator and connected to the lever as by link 84 (Fig. 1). Lever 82 is secured to a shaft I! mounted vertical- 5 iv and turning in a boss 88 depending from the inner side of cover plate II which is secured re-- when the detent engages the middle detent socket Q the tr liillld. is he in nellfi l-L w u 20 beingthenintheposltlonshewninl'igsdandd. Ifleverismovedtoshifttllsoastocause socketflatobebythedetenaclutch memberflwillinterlockwlthclntchmunber and thetonwillbecoupledtodrivethe as carforward.. Ifleverilbemovedoppositehso astocausedetentballllltoemsgedetentsocket 94b, gear I. will mesh with gear I. Then the .transmissionwillbecoupledinreverse,theilow of power from the enginelly-pessing the friction transmission the power elements of whichwillmtnteidlyinreva'se.

'Iclaim:

1. The combination of a friction roller transmission mechanism. a power input shaftforoper- 8i ating said roller on mechanism, a power output shaft operable by the roller mechanism for driving the vehicle forward, means for coupling the powerinputshaftto thefriction transmission mechanism or it there-- from and a disconnectible reverse gearing disposed on the input side of said coupling for driving the output shaft in reverse. I

The combination of a mechanismcomprisingapowerinputshaftsnd anonalined power output shaft; driving and driven races coaxial with the power output shaft; inter- 'medlate rollers e the driving and driven races; forward driving gearing between the power input shaft and a driving race; reversing gearing, w comprisingm slidable gear a: one shaft and an axially flxed gear on the other shaft; means for operatively connecting or the forward driving gearing. said means comprising a clutch element rigidwith one member of the 5 forward driving gearing, a companion clutch element fixed to the slidable gate! the reversing gearing, and control means-for sliding the composite reversing gear and clutch element so as to couplethe input shaft operatively to the driving race, to uncouple the input shaft and driving race and meshthereversing gearsortouncouplehoth the forward driving clutch and flse reversing gears i 3. The combination of a on means--05 nismcomprisingapowerinm1tshsft,a'power output shaft, axially alined driving and driven races coaxial witlij-the power output shaft. the driven races having a torque-transmitting connectionf with the power output friction rollers interposed between said races, means for coupling the power input shaft to the driving race or for uncoupling it therefrom, and disconnectible reversegearing on the power input side of said coupling between the input shaft and output shaft for driving the output shaft in reverse.

4. The combination of a transmission mechanism comprising a. power input shaft, a power output shaft out of alinement with the power input shaft, driving and driven races coaxial with the power output shaft, the driven races having a torque transmitting connection with the power output shaft, friction rollers interposed between t said races, means for operatively connecting or disconnecting the input shaft and driving race, reversing gearing between said shafts at the power input side of said means, and means for operatively connecting or disconnecting the reversing gearing.

JACOB EHRLICH. 

